A Method for Grasping a Row of Multiple Blocks of Frozen Food Originating from a Plate Freezer, and Various Uses Thereof

ABSTRACT

A method for grasping a row of multiple separate blocks of frozen food originating from a plate freezer, the row extending in a longitudinal direction corresponding to the longitudinal direction of the plate freezer, includes the steps of grasping the row of blocks along its opposing lateral edges by closing a clamp ( 1 ) having two grasping elements ( 2, 20 ) that extend along the opposing lateral edges of the row, wherein at least one of the grasping elements along its length includes multiple separate pinching elements ( 4, 40 ), each element for pinching one or more of the blocks, the pinching elements being individually movable with respect to the at least one grasping element in a direction perpendicular to the longitudinal direction of this grasping element, the method further including adjusting the lateral position of each pinching element when closing the clamp, by individually moving each pinching element.

GENERAL FIELD OF THE INVENTION

The present invention in general pertains to a method for grasping a rowof multiple separate blocks of frozen food originating from a platefreezer, the row extending in a longitudinal direction corresponding tothe longitudinal direction of the plate freezer. The invention alsopertains to a method for unloading a row of multiple blocks of frozenfood from a vertical plate freezer, a method for filling and unloading avertical plate freezer, a clamp for grasping a row of multiple blocks offrozen food, a system for filling and unloading a vertical plate freezerand a hopper for use in one of these methods or system.

BACKGROUND OF THE INVENTION

Plate freezers, in particular vertical plate freezers are commonly usedto freeze food (for human or animal consumption). A vertical platefreezer consists of a number of parallel plates, mounted vertically,through which a refrigerant runs. The plates are positionedinterdistantly to leave a row of multiple freezing compartments, alsocalled “pockets”, between the plates. The product is simply poured intothe pockets between the plates and will be frozen as blocks. A platefreezer enables rapid freezing of raw food products through its directcontact method of freezing, which offers a significant energy saving andreduced freezing time. These costs savings are also benefitted by thefact the product is poured directly into the freezer, not requiringexpensive packaging material which can increase freezing time and isliable to get damaged during use. Semi-automated loading and unloadingsystems allow a high product throughput for very low labour costs.Various types of plate freezers are described in EP 2273220 A2.

Loading typically takes place by (automatically) guiding a flexible tubeto the upper (open) side of the plate freezer. Through this tube liquidfood material is pumped into the pockets of the freezer. Unloadingtypically takes place by lifting the frozen blocks out of the pockets.Thereafter, filling plates (also called fitting panels) are manuallypositioned in between the blocks and the complete row is clamped bypressing the proximal and distal end of the row of block with fillingplates to each other using a large clamp. This way, the blocks can betransported to another location. Alternatively, no filling plates arepositioned between the blocks. In this case the blocks are firstly, verygently, moved until they are contiguous. Thereafter the row of blockscan be grasped at the proximal and distal end. This method however isvery time consuming and prone to faults due to falling block (the“Domino Effect”). A more expensive system to unload the freezer is torelease the blocks to a belt underneath the freezer, whereafter theblocks are transported by moving the belt, optionally after fillingplates have been positioned in between the blocks to try and prevent theDomino Effect.

OBJECT OF THE INVENTION

It is an object of the invention to provide for an improved method forgrasping a row of separate blocks of frozen food that can be used forunloading a plate freezer, in particular a vertical plate freezer. It isanother object of the invention to provide for an improved method andsystem for filling and unloading a vertical plate freezer. Other objectsof the invention are to provide for objects for use in these methods andsystem, in particular an improved clamp for grasping a row of multipleblocks of frozen food and a hopper for dosing liquid food material.

SUMMARY OF THE INVENTION

In order to meet the first object of the invention a method as outlinedin the GENERAL FIELD OF THE INVENTION section here above has beendevised, characterised in that the method comprises grasping the row ofblocks along its opposing lateral edges by closing a clamp having twograsping elements that extend along the said opposing lateral edges ofthe row, wherein at least one of the grasping elements along its lengthcomprises multiple separate pinching elements, each pinching elementbeing provided for pinching one or more of the blocks, the pinchingelements being individually movable with respect to the at least onegrasping element in a direction perpendicular to the longitudinaldirection of this grasping element, the method further comprisingadjusting the lateral position of each pinching element when closing theclamp, by individually moving the each pinching element with respect tothe at least one grasping element to evenly pinch the blocks (i.e. toaim at such even pinching).

Applicant found a way to overcome disadvantages of prior art graspingmethods. Applicant recognised that lateral grasping of the rows ofmultiple block of frozen food could be advantageous since this wouldmean that fitting panels or pushing the blocks together could bedispensed with: when using a clamp having two grasping elements thatextend in parallel along the length of the clamp, the row could begrasped as whole by clamping the elements to the two opposing lateralsides of the row. Since the clamping action in this case is notnegatively influenced by open spaces in the length direction of the row,the fitting panels can be dispensed with. However, grasping the row ofblocks laterally could lead to an uneven pinching of the blocks. Thelength of a typical row (3 to 5 meters) makes it difficult to constructa longitudinal grasping element that does not bend over its length(which bending would lead to less pinching pressure at the top of thebend). Moreover, given the high number of blocks of frozen food, theblocks inherently have slightly varying dimensions (even if in themillimetre range), which does result in differences in pinching pressureper block over the length of the grasping element. Without posing verystrict mechanical requirements, this results in some blocks beingcrushed laterally, while other are hardly pinched and thus cannot begrasped adequately. Imposing the needed mechanical restrictions wouldmake the freezing and grasping machines very expensive. Applicant hasdevised a solution to this problem by introducing two new features for(at least) one of the longitudinal grasping elements: the first featurebeing that the element along its length comprises multiple separatepinching elements, each element is for pinching one or more of theblocks. The second feature is that each pinching element is individuallymovable in the pinching direction.

The combined effect of these two features is that the risk of bending ofthe longitudinal grasping element is significantly lower or evenvirtually nil, and also that variations in the block dimensions dolonger affect the pinching pressure over the complete length of thegrasping element. Differences in dimensions can be adjusted locally ateach pinching element by adjusting the lateral position of each pinchingelement when closing the clamp. By individually moving the pinchingelements with respect to the grasping element, it is possible to evenlypinch the blocks even when the row is very long, even when themechanical restrictions (dimensional preciseness) of the machines do notmeet stringent demands. It is noted that the individual moving of theelements may be simply accomplished by passively adjusting the positionof the pinching elements for contacting the blocks, for example using aspring or other means to force the pinching element in a direction awayfrom the grasping element until an adequate counter force is established(due to meeting the blocks).

This new grasping method opened the way to a new method of unloading aplate freezer by grasping the blocks when forced out of the platefreezers. Next to this, it was applicant's recognition that by having aclamp available that laterally grasps the row of blocks, a new methodand system for filling and unloading a vertical plate freezer cold bedevised. This can be understood as follows. A clamp that laterallygrasps the row of blocks necessarily extends over the full length of theplate freezer. This opens the way to use the clamp not only for graspingthe blocks for unloading the plate freezer, but also for carrying alongitudinal hopper that is suitable for evenly filling the pockets ofthe plate freezer. For even automatic filling namely (“even” in thissense meaning that the larger part of the pockets, preferably more than95%, get filled for more than 80%), a hopper would need to have a lengthcorresponding to the length of the plate freezer, such that each pocketcan be dosed with the same amount of liquid food during the same timeperiod. Recognising that both the hopper and the clamp advantageouslyhave about the longitudinal dimensions, the clamp could also be used tocarry the hopper towards the plate freezer. This has the major advantagethat one transport system can be used for transporting a hopper forfilling the pockets of the freezer, as well as for the clamp to unloadthe blocks from the freezer. The resulting method for filling andunloading the freezer this way comprises taking the clamp having twograsping elements that extend in parallel along the length of the clamp,grasping a hopper with the clamp, filling the hopper with liquid food(either before or after grasping the hopper with the clamp),transporting the hopper to a dosing site above the freezer, dosing theliquid food into the freezing compartments by releasing the liquid foodfrom the hopper, freezing the food in the compartments thereby forming arow of multiple blocks of frozen food, transporting the hopper away fromthe freezer (typically right after filling of the compartments, but themoment of transport is not critical for the invention in its broadestsense), releasing the hopper from the clamp, transport the clamp back tothe freezer and grasping the row of blocks by closing the clamp alongthe opposing lateral edges of the row of multiple blocks of frozen food.

The invention also pertains to a hopper for use in any of the abovemethods or systems. This hopper has a longitudinal dosing opening with alength that corresponds to the length of the vertical plate freezer tobe filled, the opening being provided with a rotatably arranged cylinderthat closes the longitudinal opening, the cylinder being provided withat least one longitudinal slot to receive the liquid food when directedto the interior of the hopper and, after rotation of the cylinder, torelease the liquid food from the hopper when directed to the exteriorthereof.

Definitions

Automatically means without the need of operator intervention. It doesnot exclude that an action is operator initiated or stopped.

Frozen food pertains to human as well as animal food (the latter alsoreferred to as feed).

To evenly pinch multiple blocks while grasping these blocks means thatall blocks are adequately pinched, preventing on the one hand that oneor more blocks are crushed while being grasped and on the other handthat one or more blocks are not being grasped at all.

To close an opening means that the opening has a closure such thatpassage of material to be transported through the opening when open isrestricted or even completely prevented

EMBODIMENTS OF THE INVENTION

In an embodiment of the invention for grasping the row of blocks, bothgrasping elements along their respective length comprise multipleseparate pinching elements that are individually movable with respect tothe corresponding grasping element in a direction perpendicular to thelongitudinal direction of this element.

In another embodiment each pinching element has a dimension in the saidlongitudinal direction corresponding to at most three blocks. Bypinching at most three blocks, the negative influence of varyingdimensions of the blocks is decreased further.

In yet another embodiment each pinching element has a dimension in thesaid longitudinal direction corresponding to at most one block. In thisembodiment each pinching element corresponds to one block, or evenmultiple pinching elements correspond to one block. This means that evenwhen neighbouring blocks have significant different dimensions, thepinching can still be even since for each individual block the lateralposition of the pinching element(s) can be adjusted.

In still another embodiment each pinching element has a surface forgrasping the one or more blocks, wherein that the surface is roughened.This provides for more grip on the frozen blocks. In a furtherembodiment the surface comprises macroscopic teeth, preferably pivotedupwardly.

In again another embodiment each pinching element is spring loaded withrespect to the corresponding grasping element. A spring can beadvantageously used to individually adjust the lateral position of eachpinching element when closing the clamp.

In an embodiment of the new filling and unloading method according tothe invention, in which embodiment multiple vertical plate freezers areused, the method comprises consecutively filling the multiple platefreezers by transporting the hopper while grasped by the clamp to eachof the freezers, and after the food is frozen, consecutively unloadingthe freezers using the clamp for grasping at each freezer, the opposinglateral edges of the row of multiple blocks of frozen food. It was foundthat a combined use of only one clamp for filling and unloading theplate freezers even allows multiple, typically up to 10 plate freezers,to be continuously run for freezing food. Typically, when the 8^(th) to10^(th) freezer has been filled, the blocks in the first freezer aresufficiently frozen to be unloaded. The number of freezers to be runcontinuously depend i.a. on the freezing speed of these freezers.

The invention will be outlined in greater detail using the followingexamples for the clamp, hopper and combined use thereof for use in theinvention.

EXAMPLES

FIG. 1 is a schematic view of a clamp for use in the invention.

FIG. 2 is a detailed view of a pinching element of the clamp of FIG. 1.

FIG. 3 is a schematic side view of a hopper for use in the invention.

FIG. 4 is a detailed view of a closing cylinder of the hopper of FIG. 3.

FIG. 5 schematically shows the hopper of FIG. 3 carried by the clamp ofFIG. 1.

FIG. 1

FIG. 1, composed of sub-figures “a” and “b”, is a schematic view of aclamp 1 for use in the invention. As depicted in FIG. 1a , basically theclamp 1 comprises two elongated grasping elements 2 and 20, of whichonly the sides are shown in FIG. 1a . These elements have a typicallength (in the direction of view) of 3 to 6 meters, corresponding to thelength of typical (vertical) plate freezers. The grasping elements arehinged around hinge elements 3 and 30 respectively. By using hydrauliccylinders 5 and 50, the grasping elements can be moved, such that thepinching elements 4 and 40 can be moved in a direction C, perpendicularto the longitudinal direction of each grasping element. In FIG. 1a onlyone pinching element per grasping element is shown.

However, in the longitudinal direction, in this embodiment 20 of thesepinching elements per meter of length are provided. This can be seen inmore detail in FIG. 1b . In this figure, it can be seen that each of theelongated grasping elements comprises multiple pinching elements (thedetails of which pinching elements can be seen in more detail in FIG.2). Each of these pinching elements is spring loaded with respect to abar like member (only member 200 is shown in FIG. 1b ), part of theelongated grasping element.

In FIG. 1a it is shown that the clamp 1 also comprises a sprocket 6.This sprocket can be used to drive an external mechanism, in particularthe mechanism of a hopper when carried by the clamp (see FIG. 5). Theclamp is provided with chains 7 to hang the clamp from a rail system totransport the clamp through the open space.

FIG. 2

FIG. 2 is a detailed view of a pinching element 4 of the clamp ofFIG. 1. In this view only one of the multiple neighbouring pinchingelements 4 is depicted. This element is restricted in its side-waymovement using blocks 42 and 43. It is noted that this side-way movementis the longitudinal direction of the clamp and grasping element 2, ofwhich latter element part of longitudinal bar member 200 is shown inFIG. 2. The pinching element 4 can move individually with respect to thebar 200 (part of the grasping element 2) in a direction perpendicular tothe longitudinal direction of this bar. For this, each pinching elementis spring-loaded with a spring 41 with respect to bar 200. Each springpushes the corresponding pinching element forward until an equal counterforce is reached upon sufficiently pinching a block of frozen food. Inthis particular embodiment the pinching elements 4 are dimensioned inthe longitudinal direction of the clamp such that each individuallyspring loaded pinching element can only grasp one block at a time.

This way, by individually moving the pinching elements with respect tothe bar 200 of grasping element 2, the lateral position of each pinchingelement when closing the clamp is individually adjusted to enable andevenly pinch all the blocks in the row. The surface of the pinchingelements is roughened by providing macroscopic teeth 45. Such teeth, inthis case pivoted slightly upwardly, improve the grip the pinchingelements have on the blocks of frozen food.

In an alternative embodiment (not shown), three elements 4 as shown inFIG. 2 are connected at their back using a small sub-bar. This sub-baris then spring-loaded with respect to bar 200. This combined three-waypinching element is one element that can be individually moved in thesense of the present invention. In this embodiment the dimension of thepinching element in the longitudinal direction of the clamp maycorrespond to multiple blocks, for example to three blocks. This meansthat each pinching elements pinches up to three blocks at a time.

FIG. 3

FIG. 3 is a schematic side view of a hopper 100 for use in theinvention. This hopper consists of a main unit 101, which unit is openat its top end (for filling purposes) and has an opening 102 that isclosed by cylinder 103 at its bottom. The opening 102 is in fact alongitudinal rectangle that extends over the full length of the hopper(in the direction of view of FIG. 3). The cylinder first this openingand slidably closes it so that the contents of the hopper cannot freelyrun out of it. A slight leaking of fluid may arise. Hence the presenceof tray 108 underneath the hopper. This tray is for collecting fluidsthat leak from the hopper (if any) during transport. Using arm 109, thetray can be moved away from the actual opening 102 of the hopper whenthe hopper is used for filling the pockets of a plate freezer (as shownin FIG. 3).

The hopper is provided with an upper frame 110 to provide fordimensional strength and a surface for clamp 1 to carry the hopper (seeFIG. 5). Also provided is a series of sprockets 105, 106 and 107 torotate the cylinder 103, needed for dosing the contents of the hopperthrough its opening 102 to a plate freezer underneath the hopper (seeFIG. 4 for details of the dosing slots in the cylinder 103).

Although not visible in FIG. 3, the interior of the hopper is providedwith multiple transversely positioned plates to provide for adequatestiffness. This may be relevant to make sure the cylinder and openingkeep their mutual (liquid tight) arrangement, depending i.a. in thethickness of the wall of the hopper and the material to be fed. Thesetransverse plates have one or more holes to enable the liquid food to bedistributed automatically over the length of the hopper (e.g. based ongravity alone, optionally helped with a distributing means such as ascraper).

FIG. 4

FIG. 4, comprised of figures A (side view) and B (birds eye view), is adetailed view of a closing cylinder of the hopper of FIG. 3. As can beseen in FIGS. 4A and 4B, the cylinder is provided with multiplelongitudinal slots 115 slot. Each of these slots is for receiving theliquid food when directed to the interior of the hopper and, afterrotation of the cylinder 103, for releasing the liquid food from thehopper through opening 102 (see FIG. 3) when directed to this opening.

FIG. 5

FIG. 5 schematically shows the hopper 100 of FIG. 3 carried by the clamp1 of FIG. 1. In this view it can be seen that the hopper, with its frame110 rests on grasping elements 2 and 20 at locations indicated with Aand B respectively. The hopper can be released by opening the clamp, forexample when the hopper is situated while resting on a supportingstructure (not shown).

As can be seen in FIG. 5, when the hopper is carrier by the clamp, thesprocket 6 of the clamp meets the upper sprocket 105 of the hopper. Thisway, by rotating sprocket 6 using a motor (not shown) present on theclamp, the opening/closing cylinder 103 of the hopper can be actuated.

In practice, in a freezer facility up to 10 plate freezers may be filledand unloaded using one clamp and corresponding hopper. In a fillingstation, the hopper while lying stationary on a supporting structure isfilled with liquid food sufficient to fill the 10 plate freezers.Thereupon, the clamp is transported (via a rail system attached to theroof of the facility) to the hopper and the filled hopper is grasped bythe clamp as shown in FIG. 5. Then, the hopper is transported to thefirst plate freezer. When the hopper is situated exactly in line withthe plate freezer, the tray 108 is taken away from the opening and thedosing of the liquid food into the pocket starts by rotating the dosingcylinder 103. When the pockets of the freezer are all filled therotating and therewith the dosing of the liquid food is halted. Tray 108is moved back in front of the hopper opening to prevent even theslightest spilling of liquids from the hopper to the floor of thefacility. The hopper, still being carried by the clamp is thentransported to the next plate freezer. This process is repeated untilall freezers are filled with the liquid food. As soon as the lastfreezer is filled, the blocks of food in the first freezer have becomeadequately frozen. The clamp releases the hopper at its supportingstructure and is now used for unloading the blocks from the firstfreezer. After the blocks have been pushed partly out of the freezer,the row of blocks is taken from the freezer in line with the currentinvention and carried towards a downstream processing station (as knownin the art). The other freezers are unloaded the same way, in the sameorder as they have been filled. Thereafter, the whole cycle may berepeated to provide another 10 rows of blocks of frozen food.

For the present invention to be advantageously used, there is noexplicit need to fill all pockets of the plate freezer and unload themwith one and the same clamp. It is for example envisioned that two ormore clamps are being used (or the same clamp multiple times to unloadthe freezer), for example when the plate freezer is extremely long. Anyother reason however for which a clamp is used that does not have thesame length as the freezer (and thus optionally a hopper that does nothave the same length as the freezer) may be present. These variationsare also covered by the appended claims.

What is claimed is:
 1. A method for grasping a row of multiple separateblocks of frozen food originating from a plate freezer, the rowextending in a longitudinal direction corresponding to a longitudinaldirection of the plate freezer, the method comprising the steps of:grasping the row of blocks along opposing lateral edges thereof byclosing a clamp having two grasping elements that extend along the saidopposing lateral edges of the row, wherein at least one of the graspingelements along a length thereof comprises multiple separate pinchingelements, providing that each pinching element is adapted for pinchingone or more of the blocks, individually moving the pinching elementswith respect to the at least one grasping element in a directionperpendicular to a longitudinal direction of this grasping element, andadjusting a lateral position of each pinching element when closing theclamp, by individually moving each pinching element with respect to theat least one grasping element to evenly pinch the blocks.
 2. A methodaccording to claim 1, wherein both grasping elements along theirrespective length comprise multiple separate pinching elements that areindividually movable with respect to the corresponding grasping elementin a direction perpendicular to the longitudinal direction of thiselement.
 3. A method according to claim 1, wherein each pinching elementhas a dimension in the said longitudinal direction corresponding to atmost three blocks.
 4. A method according to claim 1, wherein eachpinching element has a dimension in the said longitudinal directioncorresponding to at most one block.
 5. A method according to claim 1,wherein each pinching element has a surface for grasping the one or moreblocks, and wherein the surface is roughened.
 6. A method according toclaim 5, wherein the surface comprises macroscopic teeth.
 7. A methodaccording to claim 1, wherein each pinching element is spring loadedwith respect to the corresponding grasping element.
 8. A method forunloading a row of multiple blocks of frozen food from a vertical platefreezer, the blocks forming a row of separate frozen units extending ina longitudinal direction of the plate freezer, the method comprising thesteps of forcing the row of blocks at least partly out of the platefreezer and grasping the row of blocks using a method according toclaim
 1. 9. A method for filling and unloading a vertical plate freezerfor freezing liquid food, the plate freezer comprising multiplevertically arranged parallel plates, positioned interdistantly to leavea row of multiple freezing compartments between the plates, the methodcomprising the steps of: taking a clamp having two grasping elementsthat extend in parallel along a length of the clamp, grasping a hopperwith the clamp, filling the hopper with liquid food, transporting thehopper to a dosing site above the freezer, dosing the liquid food intothe freezing compartments by releasing the liquid food from the hopper,freezing the food in the compartments, thereby forming a row of multipleblocks of frozen food, transporting the hopper away from the freezer,releasing the hopper from the clamp, transporting the clamp back to thefreezer and grasping the row of blocks by closing the clamp alongopposing lateral edges of the row of multiple blocks of frozen food. 10.A method according to claim 9, wherein multiple vertical plate freezersare used, the method comprising the steps of: consecutively filling themultiple plate freezers by transporting the hopper while grasped by theclamp to each of the freezers, and after the food is frozen,consecutively unloading the freezers using the clamp for grasping ateach freezer, the opposing lateral edges of the row of multiple blocksof frozen food.
 11. A method according to claim 9, wherein the clampalong a length thereof comprises multiple separate pinching elements,each element for pinching one or more blocks, comprising the steps of:individually moving the pinching elements with respect to the at leastone grasping element in a direction perpendicular to the longitudinaldirection of this grasping element, according to claim
 1. 12. A clampfor grasping a row of multiple blocks of frozen food originating from aplate freezer, the clamp comprising two grasping elements that extendalong a length of the clamp, wherein at least one of the graspingelements along a length thereof comprises multiple separate pinchingelements, each element for pinching one or more blocks, the pinchingelements being individually movable with respect to the at least onegrasping element in a direction perpendicular to a longitudinaldirection of this grasping element.
 13. A system for filling andunloading a vertical plate freezer comprising multiple verticallyarranged parallel plates, positioned interdistantly to leave a row ofmultiple freezing compartments between the plates for freezing liquidfood to form a row of multiple blocks of frozen food corresponding tothe multiple freezing compartments, the system comprising: a hopper fordosing liquid food into the compartments of the freezer, a clamp havingtwo grasping elements that extend in parallel along a length of theclamp, the clamp being devised to grasp the hopper, a transport totransport the clamp, while grasping the hopper, to the freezer, anarrangement to release the hopper from the clamp, and an arrangement forgrasping the row of multiple blocks of frozen food by forcing thegrasping elements to grasp opposing lateral edges of the said row.
 14. Ahopper for use in the method according to claim 9, wherein the hoppercomprises a longitudinal dosing opening with a length that correspondsto a length of a vertical plate freezer to be filled, the opening beingprovided with a rotatably arranged cylinder that closes the longitudinaldosing opening, the cylinder being provided with at least onelongitudinal slot to receive liquid food when directed to an interior ofthe hopper and, after rotation of the cylinder, to release the liquidfood from the hopper when directed to an exterior thereof.